Building your own is not hard. There's plenty of guides on the Internet on how to do it. Example like
http://pc.buildyourown.org.uk/pc-building/
I built my own gaming PC and it comes off a lot cheaper. Also worth getting an AMD processor if you wanna upgrade processor without paying for a new mobo as well in the future.
Intel change their sockets to make sure you can't do that, whereas AMD are very backwards compatible which is nice. In regards to drives, get an SSD as that will be the most noticeable addition to make your build speedy. Run your OS on the SSD as well a couple of games, keep the rest less demanding ones on a normal drive.
Also try to get a decent graphics card. Right now cards are far ahead of what people need them for. If you're running a traditional 1080p monitor then really you could get by with like a 660Ti which aren't hello expensive anymore.
Either way good luck brah